Re: [PATCH 1/5] arm64: cpufeature: Add scope for capability check

[Suzuki K Poulose]

On 14/04/16 18:38, Will Deacon wrote:
> Hi Suzuki,
>
> On Wed, Apr 06, 2016 at 12:24:10PM +0100, Suzuki K Poulose wrote:
> > Add scope parameter to the arm64_cpu_capabilities::matches(),
> > so that this can be reused for checking the capability on a
> > given CPU vs the system wide. By default, the system uses
> > 'system' wide values for setting the CPU_HWCAPs and ELF_HWCAPs.

> >   static bool __maybe_unused
> > -is_affected_midr_range(const struct arm64_cpu_capabilities *entry)
> > +is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int __unused)
>
> Maybe it would be better to WARN if somebody passes SCOPE_SYSTEM, rather
> than silently treat it as per-cpu?

Should we worry about errata's which may not necessarily depend on per CPU or
a local capability (GIC) ? If not, we could add a WARN after passing down LOCAL
scope for errata. Right now we always do SCOPE_SYSTEM from update_cpu_capabilities(), even for
cpu_errata table. There is no specific reason for that.

Cheers
Suzuki




> Will